Electric swivel connection



June 4, 1968 J. BJORN ETAL I 3,387,250

ELECTRIC SWIVEL CONNECTION Filed March 8, 1966 wi -t:

mvmox James Blorn 8 CK Marx,Jr.

United States Patent 3,387,250 ELECTRIC SWIVEL CONNECTION James Bjorn,407 N. O St, and Frederick Marx, Jr., ll0 N. D St, both of Lake Worth,Fla. 33460 Filed Mar. 8, 1966, Ser. No. 532,779 4 Claims. (Cl. 339-8)ABSTRACT OF THE DISCLOSURE The electric swivel connection comprises apair of sections of insulating material disposed in end to endrelationship, one section having an axially disposed reduced cylindricalextension on its inner fitting within a recess in the inner end of theother section; a ball bearing assembly disposed coaxially of thelongitudinal axis of the sec tions having its inner race mounted on theextension and having its outer race mounted by means of a lip in thewall of the recess in the other section to prevent separation of thesections; a fixed contact head at the center of the said extension; atyieldable contact at the center of the recess normally engaging thefixed contact and urging the sections to separate; a pair of spacedelectric contacts mounted in the outer end of the said one section; asecond pair of spaced electric contacts mounted in an annular recess inthe outer end of said other section; conductors extending through thesaid one section electrically connecting one of the first pair ofcontacts with the fixed cont-act and with the inner ball racerespectively; and other conductors extending through the said othersection electrically connecting the second pair of contacts with theyieldable contact and with the outer ball race respectively, wherebyelectric circuits will be maintained between the related contacts ofsaid pairs in all rotated positions of the sections.

Our invention is a novel electric swivel connection for use in electricpower leads and cords, and the principal object of the invention is toprovide a swivel connection so constructed that its use in a power lineto a barbers clipper or other electric device will eliminate anyobjectionable twisting and kinking of the electric lead or cord, andwill thus eliminate consequent breaking of the wires caused by suchtwisting or kinking.

A further object of our invention is to provide a novel swivelconnection of the above type which is simple in construction andeconomical to manufacture, the same comprising two parts connectedtogether by a ball bearing assembly forming part of the electriccircuit, either of which parts is capable of free rotation relative tothe other in either direction without causing kinking or breaking theleads or cords.

We will explain the invention with reference to the accompanying drawingwhich illustrates one practical embodiment there-of to enable othersfamiliar with the art to adopt and use the same, and will summarize inthe claims the novel features of construction, and novel combinations ofparts, for which protection is desired.

In said drawing:

FIG. 1 is a longitudinal section through the swivel connection.

FIG. 2 is a transverse section on the line 22, FIG. 1.

FIG. 3 is a transverse section on the line 3--3, FIG. 2.

FIG. 4 is a transverse section on the line 44, FIG. 1.

FIG. 5 is a view showing the swivel connector assembled in series withan electric cord leading to a barbers clipper, the connector beinginterposed between the cord and clipper.

As shown in FIGS. 14, our novel electric swivel connection preferablycomprises a relatively non-rotatable section A and a rotatable section Bswivelly connected together, the sections A and B being substantiallycylindrical in shape and of relatively the same diameters, and saidsections being preferably formed of suitable insulating material.

The rotatable section B is provided on its inner end with an axiallydisposed reduced cylindrical extension on which is press-fitted orotherwise secured the inner race 1 of a ball bearing assembly, the race1 being disposed coaxially of the longitudinal axis of the section B andengaged by a series of balls 2 which are also engaged by the outer race3 of the ball bearing assembly, as shown in FIGS. 1 and 3, the bearingraces 1 and 3 and balls 2 forming part of the electric circuithereinafter described.

At the center of the reduced extension on the axis of the section B is abrass or other contact 4, FIGS. 1 and 3, having its head exposed on theinner end of the section B, said head 4 preferably comprising a screwthreaded into a bore therefore at the center of the extension.

The outer or opposite end of the section B has a reduced axiallydisposed shoulder 5, and into the end of the shoulder 5 are pressed apair of spaced tubular metallic female contacts 6 and 7, respectively,as shown in FIG. 1, to receive the corresponding male plug members of anelectric plug or the like. The inner end of the tubular contact 6 isconnected by a wire 8 passing through a bore therefor to the opposite orinner end of the section B, the wire 8 being bent across said inner endand being connected electrically with the screw 4, as shown in FIGS. 1and 3, either by soldering or by means of a pressfit, whereby the head 4will form a contact electrically connected with the tubular contact 6through the body of the section B.

The other tubular contact 7 is connected by a wire 9 passing through abore therefor to the opposite or inner end of the section B, the endbeing bent over as at 9a to overlie the inner end of section B, andbeing electrically connected with the inner race 1 of the ball bearing,as shown in FIGS. 1 and 3, the connection being either by soldering, orby press-fit or otherwise, whereby the tubular contact '7 will beelectrically connected through the section B to the inner race 1 of theball bearing.

As the reduced portion 5 of the section B will be connected to thebarbers clipper C or other electric device having prongs thereon toengage the tubular contacts 6 and 7, we preferably provide means foryieldably maintaining the section B, which is rotatable, in firmconnection with the clipper C. As shown in FIGS. 1 and 2, we provide atransverse bore 10 in the reduced portion 5 disposed diametricallythereof, the ends of the bores being slightly reduced in diameter andhousing balls 11, FIG. 2, which are maintained separated by a spring 12under compression, the protruding portions of the balls 11 being adaptedto engage a corresponding groove, such as 39 (FIGS. 1 and 4), in thebore (not shown) of the clipper C to prevent ready separation of thesection B from the clipper C.

The relatively fixed section A which is connected to a plug D, FIG. 5,carried by the electric cord D has at its end adjacent the section B anannular recess 13 forming a relatively thin peripheral flange at theinner end of the section A into which is press-fitted the outer ballrace 3 of the ball hearing, as shown in FIGS. 1 and 3, the same beingmaintained in position therein by means of a lip 24 of the peripheralflange 13 which is bent over the outer end of the outer race 3 toprevent separation of the sec tions A and B after assembly.

In the base of the recess 13, disposed axially of the section A, is acontact 14 having a shank housed in a bore 15 disposed axially of thesection A on the axis thereof; and a spring 16 in the bore 15 isinterposed between the head 14 and the bottom of the bore 15 to normallyurge the q 9 0,0 3 contact 14 into firm contact with the contact 4carried by the section B to maintain electrical contact between themembers 4 and 14. The opposite end of the section A- is recessed as at17 to receive the plug D, FIG. 5, of the cord D, and at the base of therecess 17 are two spaced plug members 18 and 19 respectively, FIGS. 1and 4. As shown, the plug 18 is threaded into the section A and isconnected directly with the shank of the contact head 1% by means of awire 20 passing through a bore from the base of the bore 15 to the baseof the bore 17, the wire 20 being bent outwardly along the base of thebore 17 to meet the plug 18, and the end of the Wire 20 beingelectrically connected to the plug 18 either by soldering or bypress-fit, as shown in FIG. 1.

The other plug 19 is connected by a wire 21 leading from the base of theplug through a bore into the base of the recess 13 from whence the wire21 is bent outwardly along the base of the recess 13 and then bent tomake continuous electrical contact with the outer race 3 of the ballbearing assembly. Thus the plug 18 is in continuous electrical contactwith the contact head 14, and the plug 19 is in continuous electricalcontact with the outer race 3 of the ball bearing assembly.

By the above construction, the section A which is connected in serieswith the plug D of the cord D may remain relatively non-rotatable at alltimes, While the clipper C which is connected with the rotatable sectionB may rotate freely on the section A without twisting or kinking orbreaking the wires of the cord D; and in any rotated position of thesection B on the section A, the tubular contact 6 will be in constantelectrical connection with the plug 18 of the section A through the wire8, contact 4, contacting head 14, and wire 2t), while the tubularcontact 7 will be in constant electrical connection with the plug 19through the wire 9, the inner ball race 1, balls 2, outer ball race 3,and wire 21.

We do not limit our invention to the exact form shown in the drawing,for obviously changes may be made therein within the scope of theclaims.

We claim:

1. An electric swivel connection comprising a pair of sections ofinsulating material disposed in end to end relationship, one sectionhaving an axially disposed reduced cylindrical extension on its innerend fitting within a recess in the inner end of the other section; aball bearing assembly disposed coaxially of the longitudinal axis of thesections having its inner race mounted on the extension and having itsouter race mounted by means of a lip in the wall of the recess in theother section to prevent separation of the sections; a fixed contacthead at the center of the said extension; a yieldable contact at thecenter of the recess normally engaging the fixed contact and urging thesections to separate; a pair of spaced electric contacts mounted in theouter end of the said one section; a second pair of spaced electriccontacts mounted in an annular recess in the outer end of said othersection; conductors extending through the said one section electricallyconnecting one of the first pair of contacts with the fixed contact andwith the inner ball race respectively; and other conductors extendingthrough the said other section electrically connecting the second pairof contacts with the yieldable contact and with the outer ball racerespectively, whereby electric circuits will be maintained between therelated contacts of said pairs in all rotated positions of the sections.

2. In a connector as set forth in claim 1, a second reduced extension atthe outer end of said one section through which the first pair ofcontacts extend, said extension conforming with the annular recess inthe outer end of said other section in which said second pair ofcontacts are housed.

3. An electric swivel connection comprising a pair of cylindricalsections of insulating material disposed in end to end relationship, onesection having an axially disposed reduced cylindrical extension on itsinner end fitting within a recess of larger diameter in the inner end ofthe other section; a ball bearing assembly disposed coaxially of thelongitudinal axis of the sections having its inner race mounted on theextension and having its outer race mounted by means of a lip in thewall of the recess in the other section to prevent separation of thesections; a fixed contact head at the center of the said extension; ayieldable contact at the center of the recess normally engaging thefixed contact and urging the sections to separate; a pair of spacedelectric tubular female contacts mounted in the outer end of said onesection; a pair of spaced electric contact plugs mounted in an annularrecess in the outer end of said other section; conductors extendingthrough the said one section electrically connecting the female contactswith the fixed contact and with the inner ball race respectively; andother conductors extending through the said other section electricallyconnecting the contact plugs with the yieldable contact and with theouter ball race respectively, whereby electric circuits will bemaintained between the related female contacts and contact plugs in allrotated positions of the sections.

4. In a connector as set forth in claim 3, a second reduced extension atthe outer end of said one section through which the female contactsextend, said extension conforming with the annular recess in the outerend of said other section in which said contact plugs are housed.

References Cited UNITED STATES PATENTS 1,822,985 9/ 1931 Wright.1,973,234 9/1934 Tsavaris. 2,542,935 2/ 1951 McElroy. 2,723,380 11/1955Howard.

FOREIGN PATENTS 272,686 3/ 1951 Switzerland.

MARVIN A. CHAMPION, Primary Examiner.

RAYMOND S. STROBEL, Assistant Examiner.

